scholarly journals Novel Magnetic Resonance Imaging strategy targeting Neurotensin Receptors in detection of Prostate Cancer

2017 ◽  
Author(s):  
Mitul Desai ◽  
Neville N.C. Tam ◽  
Robert. Carraway ◽  
Shuk-Mei Ho ◽  
Craig. Ferris ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Pulse Sequence ◽  
Spin Echo ◽  
Gradient System ◽  
Data Sets ◽  
Contrast Injection ◽  
Post Contrast ◽  
Receptor Ligand

ABSTRACTProstate cancer is the second leading cause of all male cancer deaths. One of the factors present in malignant prostate cells and shown to support its metastatic growth is the neuropeptide neurotensin (NT). The primary goal of the present study was to establish the feasibility of using a newly developed paramagnetic receptor ligand for NT and non-invasive ultrahigh-field magnetic resonance (MR) imaging to visualize prostate cancer in rodents. Orthotropic xenografts were initiated in six-week old male BALB/c nu/nu athymic mice (n = 28) by intra-prostatic (ventral lobe) inoculation of human prostate cancer cells (10μL of PC3 cells (106 /100μl)). Palpable tumors developed within 30-60 days. A micro-imager utilized in these studies was an actively shielded 9.4T, 89 mm bore, Oxford superconducting magnet with a 100 gauss/cm gradient system. Prior to contrast injection, T2 weighted anatomy scans were done to localize the tumor with a spin-echo multi-slice sequence with TR: 2000 TE: 40 and NEX: 1 in both coronal and axial planes. The paramagnetic ligand data sets were collected with a spin-echo, T1 weighted pulse sequence (MSME): TR 300 msec; TE 5 msec; NEX 4 in both axial and coronal planes. The data sets were taken initially at 5-min intervals post contrast injection for the first half hour and then at 15 min intervals for the next 1.5-2 hours for a time series analyses. The temporal distribution of MR signal intensity in various regions were determined in the absence and presence of NT. Our results confirm that the novel NT molecule was protected from enzymatic degradation and capable of forming a high affinity paramagnetic NT ligand with an extended half-life. During the imaging studies, the signal intensity increased by 200 % in the region of the tumor. This increase in signal intensity approached maximum binding within 30 minutes and remained visible for 1 hour post-injection of the contrast agent. Taken together, these findings suggest that it is feasible to detect and image prostate cancer using a paramagnetic NT ligand and the emergence of the NT receptor ligand that may be used as a diagnostic marker for prostate cancer in humans.

The detection of bone marrow involvement by lymphoma using magnetic resonance imaging.

1987 ◽  
Vol 5 (2) ◽  
pp. 225-230 ◽  
Author(s):  
A F Shields ◽  
B A Porter ◽  
S Churchley ◽  
D O Olson ◽  
F R Appelbaum ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Signal Intensity ◽  
Imaging System ◽  
Pulse Sequence ◽  
Spin Echo ◽  
Bone Marrow Involvement ◽  
Marrow Fat ◽  
Spin Echo Sequence

We used magnetic resonance (MR) to image the bone marrow of 31 patients with lymphoma. Images were obtained of the femoral, pelvic, and vertebral marrow with a 0.15 tesla imaging system using a T1-weighted spin echo sequence (TR600/TE 40). With this pulse sequence, normal marrow produces a high intensity signal that reflects the presence of marrow fat (short T1 relaxation time). We previously reported MR imaging of patients with leukemia in relapse and found a diffusely and symmetrically decreased marrow signal intensity due to the replacement of normal marrow fat by cellular material with a long T1. Unlike leukemia, patients with lymphomatous marrow involvement often had patchy, often discrete, areas of low signal intensity, representing focal marrow infiltration. Five of six patients in this study with lymphoma detected by histologic examination also had marrow lesions seen on MR. An additional four patients had marrow lesions detected by MR that were not detected on initial marrow biopsies; two of these had marrow involvement proven on subsequent biopsies, one had disease isolated to the vertebrae that was never pathologically documented, and one had progression of disease in the marrow documented by MR without biopsy confirmation. These results indicate that marrow involvement with lymphoma can be detected by MR imaging and that MR can complement bone marrow biopsy.

Quantitative analysis of unruptured intracranial aneurysm wall thickness and enhancement using 7T high resolution, black blood magnetic resonance imaging

2021 ◽  
pp. neurintsurg-2021-017688
Author(s):  
Xinke Liu ◽  
Junqiang Feng ◽  
Zhixin Li ◽  
Zihao Zhang ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Wall Thickness ◽  
Signal Intensity ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Black Blood ◽  
Post Contrast ◽  
Isotropic Resolution ◽  
Aneurysm Size ◽  
Aneurysm Wall

BackgroundThis study was performed to quantify intracranial aneurysm wall thickness (AWT) and enhancement using 7T MRI, and their relationship with aneurysm size and type.Methods27 patients with 29 intracranial aneurysms were included. Three-dimensional T1 weighted pre‐ and post-contrast fast spin echo with 0.4 mm isotropic resolution was used. AWT was defined as the full width at half maximum on profiles of signal intensity across the aneurysm wall on pre-contrast images. Enhancement ratio (ER) was defined as the signal intensity of the aneurysm wall over that of the brain parenchyma. The relationships between AWT, ER, and aneurysm size and type were investigated.Results7T MRI revealed large variations in AWT (range 0.11–1.24 mm). Large aneurysms (>7 mm) had thicker walls than small aneurysms (≤7 mm) (0.49±0.05 vs 0.41±0.05 mm, p<0.001). AWT was similar between saccular and fusiform aneurysms (p=0.546). Within each aneurysm, a thicker aneurysm wall was associated with increased enhancement in 28 of 29 aneurysms (average r=0.65, p<0.05). Thicker walls were observed in enhanced segments (ER >1) than in non-enhanced segments (0.53±0.09 vs 0.38±0.07 mm, p<0.001).ConclusionImproved image quality at 7T allowed quantification of intracranial AWT and enhancement. A thicker aneurysm wall was observed in larger aneurysms and was associated with stronger enhancement.

Contrast magnetic resonance imaging for measurement of cartilage glycosaminoglycan content in dogs: A pilot study

2013 ◽  
Vol 26 (02) ◽  
pp. 100-104 ◽  
Author(s):  
M. C. Stewart ◽  
L. Ciobanu ◽  
P. D. Constable ◽  
J. F. Naughton
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Coefficient Of Variation ◽  
Signal Intensity ◽  
Linear Regression Analysis ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Enhanced Mri ◽  
Over Time

SummaryObjective: To assess the ability of a contrast-enhanced magnetic resonance imaging (MRI) technique to quantitatively determine glycosaminoglycan content in canine articular cartilage.Methods: Fifty-four full-thickness cartilage discs were collected from the femorotibial and scapulohumeral joints of three adult dogs immediately following euthanasia. One set of discs from each dog was analysed for glycosaminoglycan content using a colourimetric laboratory assay. The remaining position-matched set of discs from contralateral limbs underwent pre- and post-contrast gadolinium-enhanced MRI, using repeated saturation recovery pulse sequences which were used to generate calculated T1 maps of the cartilage discs. Linear regression analysis was then performed relating delayed gadolinium-enhanced MRI T1 calculated signal intensity to the cartilage glycosaminoglycan content normalized to DNA content. Repeatability of triplicate measurements was estimated by calculating the coefficient of variation.Results: Mean coefficient of variation estimates for the gadolinium-enhanced MRI T1 signal intensity values for nine sampling sites from three dogs ranged from 5.9% to 7.5%. Gadolinium-enhanced MRI T1 signal intensity was significantly correlated (p <0.05) with normalized glycosaminoglycan content in two dogs (r = 0.79, p = 0.011; r = 0.78, p = 0.048), but not in the third dog (r = 0.53, p = 0.071).Clinical significance: Gadolinium-enhanced MRI assessment of cartilage may be predictive of glycosaminoglycan content and therefore offer an in vivo assessment of changes in cartilage characteristics over time. Additional studies appear indicated to determine the reliability and clinical applicability of gadolinium-enhanced MRI in detecting changes in cartilage over time.

scholarly journals Accelerated high-resolution free-breathing 3D whole-heart T2-prepared black-blood and bright-blood cardiovascular magnetic resonance

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Teresa Correia ◽  
Giulia Ginami ◽  
Imran Rashid ◽  
Giovanna Nordio ◽  
Reza Hajhosseiny ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Healthy Subjects ◽  
Free Breathing ◽  
Black Blood ◽  
Contrast Injection ◽  
Post Contrast ◽  
Whole Heart ◽  
Bright Blood

Abstract Background The free-breathing 3D whole-heart T2-prepared Bright-blood and black-blOOd phase SensiTive inversion recovery (BOOST) cardiovascular magnetic resonance (CMR) sequence was recently proposed for simultaneous bright-blood coronary CMR angiography and black-blood late gadolinium enhancement (LGE) imaging. This sequence enables simultaneous visualization of cardiac anatomy, coronary arteries and fibrosis. However, high-resolution (< 1.4 × 1.4 × 1.4 mm3) fully-sampled BOOST requires long acquisition times of ~ 20 min. Methods In this work, we propose to extend a highly efficient respiratory-resolved motion-corrected reconstruction framework (XD-ORCCA) to T2-prepared BOOST to enable high-resolution 3D whole-heart coronary CMR angiography and black-blood LGE in a clinically feasible scan time. Twelve healthy subjects were imaged without contrast injection (pre-contrast BOOST) and 10 patients with suspected cardiovascular disease were imaged after contrast injection (post-contrast BOOST). A quantitative analysis software was used to compare accelerated pre-contrast BOOST against the fully-sampled counterpart (vessel sharpness and length of the left and right coronary arteries). Moreover, three cardiologists performed diagnostic image quality scoring for clinical 2D LGE and both bright- and black-blood 3D BOOST imaging using a 4-point scale (1–4, non-diagnostic–fully diagnostic). A two one-sided test of equivalence (TOST) was performed to compare the pre-contrast BOOST images. Nonparametric TOST was performed to compare post-contrast BOOST image quality scores. Results The proposed method produces images from 3.8 × accelerated non-contrast-enhanced BOOST acquisitions with comparable vessel length and sharpness to those obtained from fully- sampled scans in healthy subjects. Moreover, in terms of visual grading, the 3D BOOST LGE datasets (median 4) and the clinical 2D counterpart (median 3.5) were found to be statistically equivalent (p < 0.05). In addition, bright-blood BOOST images allowed for visualization of the proximal and middle left anterior descending and right coronary sections with high diagnostic quality (mean score > 3.5). Conclusions The proposed framework provides high‐resolution 3D whole-heart BOOST images from a single free-breathing acquisition in ~ 7 min.

scholarly journals Correlative Magnetic Resonance Imaging and Histopathology in Small Ruminant Listeria Rhombencephalitis

2020 ◽  
Vol 11 ◽  
Author(s):  
Christina Precht ◽  
Peter Vermathen ◽  
Diana Henke ◽  
Anne Staudacher ◽  
Josiane Lauper ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Enhancement ◽  
Signal Intensity ◽  
Small Ruminants ◽  
Large Animal ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Mri Features ◽  
Inflammatory Infiltrates

Background: Listeria rhombencephalitis, infection of the brainstem with Listeria monocytogenes, occurs mainly in humans and farmed ruminants and is associated with high fatality rates. Small ruminants (goats and sheep) are a large animal model due to neuropathological similarities. The purpose of this study was to define magnetic resonance imaging (MRI) features of listeria rhombencephalitis in naturally infected small ruminants and correlate them with histopathology. Secondly, the purpose of this study was to compare the results with MRI findings reported in humans.Methods: Twenty small ruminants (13 sheep and 7 goats) with listeria rhombencephalitis were prospectively enrolled and underwent in vivo MRI of the brain, including T2-weighted, fluid attenuation inversion recovery, and T1-weighted sequences pre- and post-contrast administration and postmortem histopathology. In MRI, lesions were characterized by location, extent, border definition, signal intensity, and contrast enhancement. In histopathology, the location, cell type, severity, and chronicity of inflammatory infiltrates and signs of vascular damage were recorded. In addition, histopathologic slides were matched to MRIs, and histopathologic and MRI features were compared.Results: Asymmetric T2-hyperintense lesions in the brainstem were observed in all animals and corresponded to the location and pattern of inflammatory infiltrates in histopathology. Contrast enhancement in the brainstem was observed in 10 animals and was associated with vessel wall damage and perivascular fibrin accumulation in 8 of 10 animals. MRI underestimated the extension into rostral brain parts and the involvement of trigeminal ganglia and meninges.Conclusion: Asymmetric T2-hyperintense lesions in the brainstem with or without contrast enhancement can be established as criteria for the diagnosis of listeria rhombencephalitis in small ruminants. Brainstem lesions were similar to human listeria rhombencephalitis in terms of signal intensity and location. Different from humans, contrast enhancement was a rare finding, and abscessation was not observed.

scholarly journals Detection of pancreatic fibrosis using magnetic resonance imaging: correlation with histopathology

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Carsyn Kranz ◽  
Omer Saeed ◽  
Vitalis Osuji ◽  
Evan Fogel ◽  
Nicholas Zyromski ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Interobserver Agreement ◽  
Weighted Kappa ◽  
Pancreatic Fibrosis ◽  
Imaging Biomarkers ◽  
Fibrosis Score ◽  
Resonance Imaging ◽  
Post Contrast

Background and Hypothesis: Diagnosis of chronic pancreatitis (CP) is challenging and controversial. Magnetic Resonance Imaging (MRI) offers a noninvasive modality to diagnose CP, but its findings have been rarely correlated with histopathology. We aimed to assess the correlation of T1 signal intensity ratio of pancreas to spleen (T1 SIRp/s) and arterio-venous ratio (AVR) of the parenchyma on MRI and Cambridge score on MRCP with surgical histopathology in patients who underwent pancreatic resection.  Methods: We identified 160 pancreatic resections performed in adults between 2017 and 2019 by searching our institution’s surgery database. Seventy-one of them had surgical pathology specimens available and 59 of them had MRI/MRCP within 3 months prior to the surgery. Histologic grading was performed by a gastrointestinal pathologist using Ammann’s fibrosis score. Two image analysts blinded to the clinical information and fibrosis score measured T1 SIRp/s from unenhanced T1-weighted fat-saturated gradient-echo images and arterio-venous ratio (AVR) from post-contrast dynamic phase. Cambridge score was also recorded from MRCP. Statistical analysis included Pearson’s correlation coefficient of the T1 SIRp/s, AVR, and Cambridge score with the fibrosis score and weighted kappa for interobserver agreement.  Results: Correlations between T1 SIRp/s and AVR with the fibrosis score were (r= -0.30, p=0.02, 95%CI: -0.51 to -0.04 and r= -0.36, p=0.01, 95%CI: -0.58 to -0.09, respectively). In comparison, there is less correlation between the Cambridge grade and the fibrosis (r= 0.17, p=0.15, 95% CI for r= -0.07 to 0.39). Interobserver agreement was good (kappa=0.80).  Conclusion: There is moderate correlation between the T1 signal intensity and enhancement ratio of the pancreas with pancreatic fibrosis. This is higher than the correlation between the Cambridge grade and fibrosis. Multi-institutional, prospective studies are needed to verify T1 SIR and AVR as potential imaging biomarkers of pancreatic fibrosis. 

scholarly journals In Vivo 3T Magnetic Resonance Imaging Using a Biologically Specific Contrast Agent for Prostate Cancer: A Nude Mouse Model

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Christopher Brian Abraham ◽  
Prashant Jani ◽  
Roxanne Turuba ◽  
Michael Campbell ◽  
Ingeborg Zehbe ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prostate Cancer ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Inductively Coupled Plasma ◽  
Spin Echo ◽  
Resonance Imaging ◽  
Nude Mouse Model

We characterized in vivo a functional superparamagnetic iron-oxide magnetic resonance contrast agent that shortens the T2 relaxation time in magnetic resonance imaging (MRI) of prostate cancer xenografts. The agent was developed by conjugating Molday ION™ carboxyl-6 (MIC6), with a deimmunized mouse monoclonal antibody (muJ591) targeting prostate-specific membrane antigen (PSMA). This functional contrast agent could be used as a noninvasive method to detect prostate cancer cells that are PSMA positive and more readily differentiate them from surrounding tissues for treatment. The functional contrast agent was injected intravenously into mice and its effect was compared to both MIC6 (without conjugated antibody) and phosphate-buffered saline (PBS) injection controls. MR imaging was performed on a clinical 3T MRI scanner using a multiecho spin echo (MESE) sequence to obtain T2 relaxation time values. Inductively coupled plasma atomic emission spectroscopy was used to confirm an increase in elemental iron in injected mice tumours relative to controls. Histological examination of H&E stained tissues showed normal morphology of the tissues collected.

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